The correlation between transient osteoporosis of the hip and pregnancy: A review

Transient osteoporosis of the hip is indubitably a comparatively infrequent entity affecting both men and women worldwide. Its occurrence in the course of pregnancy, specifically in the third trimester, and lactation are of paramount concernment. The exact association between transient hip osteoporosis and pregnancy is precarious. Etiology and potential pathophysiological mechanisms behind this correlation are still to be utterly defined. Magnetic resonance imaging is highly regarded as the gold standard imaging method for assiduous assessment of this disorder. Physicians of copious medical specialties should practice scrupulous techniques for early and pertinent diagnosis when pregnant women are presented with persistent hip pain, as differential diagnosis with femoral head avascular necrosis can be exceedingly arduous. Treatment is predominantly conservative with protected weight-bearing and analgesic medication in the first line of management. In terms of prognosis, the disease ordinarily resolves spontaneously after a few months. Further research is required in order to elucidate the ambiguity surrounding the establishment of globally approved diagnosis and treatment guidelines for pregnancy-associated transient hip osteoporosis. This paper aims to accentuate the significance of this particular disorder by providing a succinct review of the existing literature, augmenting clinicians’ knowledge about the features of pregnancy-related transient proximal femur osteoporosis.


Introduction
4][5] Hip is the most ordinarily affected site (76%), although knees, feet and ankles can be afflicted as well.Hip movement is usually limited by a rapid-onset hip pain, expanding to the groin and thigh, triggering weight-bearing arduousness.
The first 3 cases of TOH in pregnancy were reported by Curtiss and Kincaid in 1959, presenting patients with unilateral or bilateral hip pain or groin pain in the third trimester of pregnancy.Radiology evaluation demonstrated severe osteopenia of the femoral head, femoral neck and acetabulum, which exhibited rapid recovery several months postpartum, while similar cases were delineated at a subsequent time. [6]tiology and pathophysiology of pregnancy-associated TOH are still vague.Conventionally, osteoporosis is correlated with estrogen deficiency.Contrariwise, pregnancy is a state of excess estrogen production, while osteoporosis, which is chiefly unilateral, is presumably arising from impaired venous return and bone marrow edema. [5,7,8]It is not uncommon for some patients to display past medical history of conditions linked to decreased bone mineral density (BMD) and bone mass.When these conditions are linked with the mechanical and metabolic stress during pregnancy and breastfeeding, a rise in bone turnover along with venous hypertension and/or microfractures can cause edema. [5,7,8]A rare complication can be progression to avascular necrosis (AVN). [8]dditionally, it has also been documented that women demonstrating no risk factors can potentially develop pregnancy-associated TOH.During lactation period, loss of bone mass can be inexorable, prompting an evanescent fracture-risk upsurge.[9] It has not been determined whether osteoporosis medication approved in general population should be used during pregnancy, strikingly because there is lack of pertinent evidence and cause pregnancy-associated TOH is regarded as a benign and self-limiting condition. [9]t is pivotal to emphasize that pregnancy-associated osteoporosis (PAO) is a distinct material malady, which might also transpire in physically-fit pregnant women in the third trimester or during the first months postnatal.Predominantly, fractures respond to the thoracolumbar spine and principally from T11 to L2, causing significant height loss. [9]Several theories exist concerning PAO etiology and pathophysiology, but the exact cause is yet to be defined. [9]n this paper, an overview of present-day knowledge surrounding the etiology, management and therapy of pregnancy-associated TOH is presented.Owing to the lack of consensus concerning classification, treatment and outcome scores, establishing apposite guidelines or algorithms is exceedingly strenuous.We endeavor to provide an up-to-date knowledge that might guide the obstetricians/gynecologists and orthopedic surgeons when dealing with pregnancy-associated TOH, bolstering their expertise among the variety of clinical presentations and the optimal combination of therapies.

Materials and methods
Literature search was conducted utilizing the MEDLINE/PubMed and Google Scholar databases for articles published from 1959 up to 2023.Keyword search terms were: "transient," "osteoporosis," "hip" and "pregnancy."Language filters were activated for English.No restrictions were implemented in terms of the scientific articles' publication date.Inclusion criteria were clinical studies, case series, reviews and papers reporting clinical cases.Exclusion criteria were papers presenting trials or cases about PAO and AVN in pregnancy.Articles in full text were scrutinized to retrieve additional relevant studies.Article selection was executed independently by 2 authors that employed the aforementioned inclusion criteria, whilst disagreements were elucidated with the contribution of a third author that made the decision.The collected data were entered into an Excel spreadsheet.

Results and discussion
A total of 345 papers were reviewed and 181 articles were selected for rigorous assessment.Following a full-text review, 11 additional articles were included from manual bibliographic search, perusing the pages of key journals and scanning reference lists of identified articles and documents.61 papers were finally selected for citation (Fig. 1, Table 1).

Skeletal adaptations during pregnancy/lactation and pathophysiology
Pathophysiology of pregnancy-related TOH is equivocal, though several hypotheses have been postulated.
Affected regions are characterized by bone marrow edema and enhanced bone turnover. [10]A combination of factors suggested to tally with this condition, are pregnancy-associated factors such as: immobilization, femoral venous stasis, obturator nerve pressure and hormonal variations of pregnancy, apart from traditional breastfeeding and osteoporosis risk factors involving: infective or inflammatory diseases, previous trauma, vascular lesions, neoplasia, alcoholic consumption, smoking, steroids, medications intake, hypothyroidism, low vitamin D or osteogenesis imperfecta. [4,11]uring pregnancy, several maternal adaptations occur for supplying the required calcium.The proportion of intestinal calcium absorption doubles, which is featured to be principally expedited by raised 1,25-dihydroxyvitamin D (1,25-OH D) levels generated by the maternal kidneys, [11,12] albeit, other factors such as prolactin and placental lactogen may also contribute. [11]ther alterations include parathyroid hormone (PTH) diminution and PTHrp increase precipitated by the placenta and bosoms, which are considered to conduce to the augmentation of 1,25-OH D by stimulating renal 1-alpha hydroxylase. [12]erum calcium dwindles in parallel with albumin, but levels of ionized calcium do not alter. [12]tudies of BMD variations occurring in human pregnancy are broadly considered limited, contrasting BMD calculations conducted before pregnancy with those acquired postnatal.The biggest study examining BMD alterations in pregnancy was carried out by Moller et al in 2012. [13]This study recorded 92 women who got pregnant, performing DEXA scans of lumbar spine, hip, and total body before pregnancy and then at 2 weeks, 4 months, and 9 months postnatal, respectively.Additionally, DEXA scans of forearm were conducted during each pregnancy trimester.The research involved a control group of 75 women who did not get pregnant for juxtaposition.73 and 57 women in the corresponding groups, got through the first follow-up.BMD in the pregnant group was found to decline by a mean of 1.8 (±0.5%) in terms of the lumbar spine, 3.2 (±0.5%) regarding total hip and by 2.4 (±0.3%) concerning the total body, contrasting pre-pregnancy figures with those measured 2 weeks postnatal.Ultra-distal forearm BMD revealed a noteworthy, gradual abatement in pregnancy, and total forearm BMD was pronouncedly reduced by the 3rd trimester.Regulating for body weight/body composition alterations in pregnancy did not substantively modify these outcomes.Notwithstanding being statistically important, the documented BMD alterations in this research were minor. [13]A conspicuous limitation of this paper was that by the time of 2-week postnatal follow-up visit, a crucial impact of early lactation cannot be precluded. [12]oncerning bone structure, in a contemporary paper by Breasail et al, pQCT and HRpQCT were employed for collation of tibia and radius changes in pregnant women aged 30 to 45 with a control group of non-pregnant, non-breastfeeding females. [14]In particular, 46 pregnant women and 37 non-pregnant controls were involved in that study.Reference scans at 14 to 16 weeks of pregnancy were contrasted to follow-up scans at a median of 35.8 weeks pregnancy.Larger pQCT figures depletion was observed in the pregnant group regarding total and trabecular vBMD, while greater decrease in total vBMD and cortical BMD was computed by HRpQCT.These alterations were predominately discernible in the tibia region, whilst concerning the radius area, solely the cortical bone-abundant proximal region demonstrated a discrepancy between the groups, with a cortical thickness reduction and enhancement in endosteal circumference detected in the pregnant group.The researchers conjectured that these outcomes might connote a differential pregnancy impact on bone architecture between weight-bearing and non-weight-bearing areas. [14]Preponderantly, these data propound that albeit gestation does prompt some moderate affections on maternal skeleton regarding both BMD and bone structure, hormonal gestation adjustments secure that most fetal calcium necessities during pregnancy itself are attained via augmented calcium absorption from the mother sustenance.
Contrarily to gestation, during breastfeeding, maternal skeletal resorption is the principal adjustment guaranteeing an adequate calcium supply for milk-making.Skeletal calcium is produced by osteoclast-mediated bone resorption and osteolysis by osteocytes, incited by PTHrp from bosom tissue and little estradiol levels. [12]Throughout breastfeeding, the kidneys do preserve calcium, however, intestinal calcium absorption returns to prior-pregnancy levels.Therefore, they are no more a salient factor in securing calcium requirements are fulfilled. [12]longside that, circulating 1,25-OH D swiftly reverts to prior-pregnancy levels post childbirth. [12]Maternal calcium input, either from diet or supplements, does not seem to amend intestinal calcium uptake rate or bone resorption, plainly resulting in upraised urinary calcium levels. [12]ontrarily to pregnancy, throughout lactation, bone-turnover markers investigations reveal a noticeable rise in bone resorption markers compared with levels prior to/ during pregnancy. [12]The majority of studies indicate that bone formation markers are raised as well, yet, to a smaller extent.This is indicative of uncoupling, prompting net resorption, [12] a familiar resultant of estrogen insufficiency. [15]BMD research exhibits weighty BMD reduction at all regions during 6 months of lactation.The biggest decrease (5%-10% averagely) is discovered in lumbar spine, with lower drop (up to 5%) at the hip/femur/ distal radius areas, and only 0% to 2% lessening concerning total body calculations. [12]This adduces that bone resorption throughout breastfeeding is more extensive at trabecular-rich areas, with cortical bone being less impacted.Nonetheless, there is an essential interindividual discrepancy concerning the amount of bone loss throughout breastfeeding, with a portion of women being deprived of up to 20% of their lumbar spine BMD, causing them to be osteoporotic. [16]As anticipated, breastfeeding period is commensurate to the BMD abatement identified. [17]Following the first 6 months, there are data suggesting  Cross-sectional study

Netherlands
The purpose of this study was to report the signs and symptoms of pregnant women with pain and dysfunction in the pelvic area.

Medline/ Pubmed
Pregnant patients with pelvic pain exhibited a material level of complaints.that BMD does begin rising again in females carrying on lactation, presumably due to weaning that results in diminished feeding demand, nonetheless, at 12 months BMD is still found below reference levels. [17]One paper denoted that BMD exhibits signs of recovery once menstruation recommences, even if breastfeeding carries on. [18]thors (yr)

Medline/ Pubmed
Although the risk of osteoporotic fractures correlated to unfractionated heparin is limited (≤2%), subclinical depletion of bone density can occur in 1-third of women receiving the agent long-term.It is contentious whether the reduced bone density connected with therapy is substantially greater than the impact of pregnancy alone on bone density.Also, it is debatable whether dosage and duration of heparin therapy correlate with the extent of osteopenia.M. Backos et al  (1999)   Prospective study UK Prospective study of the bone mineral density (BMD) alterations during pregnancy and the puerperium in 123 women with primary antiphospholipid syndrome treated with low-dose aspirin and subcutaneous low-dose heparin

Medline/ Pubmed
Pregnant women demanding thromboprophylaxis can be encouraged that the loss in lumbar spine BMD related to low-dose long-term heparin treatment is similar to that which happens physiologically during pregnancy.
AVN = avascular necrosis.Also, a mechanical factor has been implied for increasing the risk of TOH.Specifically, the left common iliac vein passes under the right common iliac artery, hence, the vein is more susceptible to compression.21][22] Perusing literature, the left hip was most frequently involved, chiefly in the 3rd trimester or shortly postpartum, which is supportive of this mechanical theory. [19,20,22,23]Though improbable, bone marrow edema may progress provoking vascular compression, leading to femoral head ischemic injury and AVN.AVN and hip osteonecrosis tend to respond in primigravida and in relatively elderly women. [19,24]ccording to a literature review conducted by Quaresima P. et al, [25] the majority of pregnancy-associated TOH cases have been reported without the presence of any risk factors.In a case control study, Peyman Hadji et al were the only ones to have investigated the potential definite pregnancy-related TOH risk factors.The outcomes pointed out that immobility, dental problems and lack of childhood exercise are eloquently correlated to the aforementioned disease. [26]

Clinical characteristics and etiology
Clinical presentation of TOH is customarily portrayed as an abrupt pain onset located in the groin region, anterior thigh and buttocks, which can involve one or both hips. [9]Hip or pelvic pain throughout gestation is an accustomed complaint with an incidence rate ranging from 38% to 56%. [27,28]Most of these complaints are benign, deriving from ligamentous strain at the pelvis and lumbar spine. [29]Thus, vigilant physical examination is cardinal for distinguishing between hip and pelvic pathologies and can be eminently salutary, however, it can be also inaccurate and deceptive. [30]In particular, TOH can be misdiagnosed as simple sciatica or sacroiliac strain. [31]The most contemporary research concerning females diagnosed with TOH at a sole hospital was conducted by Toussia-Cohen S. et al. [32] In this study, both obstetric and clinical features and findings of 34 pregnant females identified with TOH during gestation or postnatal period were reported and analyzed. [32]he utmost findings of this study included: a comparatively increased maternal age (average age of mothers was 34.18 ± 4.75 years), the conspicuous preponderance of family history of non-PAO (29.4%) and escalated smoking proportions (47.1%), as well as women low prior-pregnancy body mass index (BMI) and at childbirth (22.03 and 27.60, correspondingly).Also, the proportion of in vitro fertilization (IVF) conception was relatively high (32.4%).Possible rationale behind the increased IVF conception rate might be the analogously increased median maternal age, along with the various medications employed in IVF treatments that have been formerly documented as TOH risk factors. [9]In particular, 9 females (26.5%) were confirmed with bilateral TOH, a finding featuring material clinical significance, connoting that guidance involving weight-bearing abatement might be practicable in terms of both legs, hence, early imaging and diagnosis are vital.Clinical outcomes were not glaringly dissimilar between vaginal deliveries and c-section deliveries.What more, 2 women (13.3%) were reported with TOH in a sequential gestation. [32]egarding maternal age at the time of TOH diagnosis, in the review paper by Quaresima et al, [25] average mothers age was 32.10 ± 5.50 years.Notwithstanding, Hadji et al [26] reported 33 pregnant females identified with TOH in which the average age was found 35.20 ± 4.10 years.
In the study carried out by Toussia-Cohen S. et al, relatives medical record of pregnancy-unrelated osteoporosis was observed in 29.4% of cases, which was not documented in previous papers as a predisposing factor for TOH.It is vitally weighty to mention that the pathophysiological pathways of both entities are utterly dissimilar, and therefore the association betwixt the 2 is ambiguous.Moreover, at the same study, the percentage of smokers (47.1%) was notably large contrasted to studied smoking figures during gestation of just 6.7% in the United States in 2017. [33]Consequently, smoking could be regarded a key predisposing factor for pregnancy-associated TOH as reported in preceding studies. [34] previous publication from Hadji P. et al revealed that women with TOH demonstrated a 2 kg bigger mean body weight contrasted to females without TOH, [26] which is supportive of the mechanical theory.Nevertheless, these findings are conflicting with the study of Toussia-Cohen S. et al, [32] which delineated that women BMIs, both prior-pregnancy and at childbirth (22.03 and 27.6, correspondingly), are comparatively small contrasted to average BMI figures in the population (24.7 and 29.7, correspondingly).Papers concerning non-transient osteoporosis have deduced that increased BMI ameliorates BMD, ergo reducing fracture danger, whilst small-scale BMI is a well-recorded risk factor for osteoporotic fractures. [35]n terms of anticoagulants (mainly low molecular weight heparin [LMWH]) that are utilized as first-line agents for venous thromboembolism prevention, data regarding this treatment osteopenic effect are somewhat contradicting. [35]Long-term LMWH prophylaxis in gestation for a minimum of 3 months has been correlated to bone loss and fractures, [36][37][38] nevertheless, other studies indicated that the absolute fracture risk in this specific group was narrow (1%-2%). [39]Additionally, BMD decreases of 2% to 4% prompted by the prophylactic doses of LMWH or unfractionated heparin were contiguous to the drop in bone mass that transpires customarily in gestation. [40,41]In the study of Toussia-Cohen S. et al, [30] antithrombotic prophylaxis owing to dwindled mobilization was employed in 29.4% of patients only for several months, with this limited use not expected to expose the women to an enhanced fracture danger.
Regarding delivery mode, a case-control study conducted by Hadji et al [26] demonstrated that females with TOH featured increased rates of elective CD contrasted to females in good health.Also, Quaresima et al described TOH as a non-obstetric sign for cesarian section. [25]In the study of Toussia-Cohen S. et al [32] comparing delivery mode between women identified with TOH, only 5 women (31.2%) were admonished to proceed to elective cesarian delivery owing to TOH, this being the first report of such a comparison.This finding was ascribed to the cumulated familiarity with TOH patients, in addition to enhanced magnetic resonance imaging (MRI) scan availability that offers physicians the reassurance to permit pregnant females with TOH to attempt delivering vaginally. [32]oncerning diagnosis timing, physicians ought to be tremendously aware of groin pain in the postnatal period, chiefly taking into account that medical monitoring at this period is patently limited than during gestation, considering carrying out an MRI scan in cases of acute persistent pain.

Differential diagnosis and imaging
Pregnancy-related TOH radiographic evaluation typically reveals the presence of osteopenia 4 to 6 weeks after the symptoms' onset.However, MRI, which is indubitably a safe examination for pregnant women, is regarded as the optimum method for depicting bone marrow edema and abnormalities that can be descried as early as 48 hours after the emergence of symptoms. [42,43]MRI findings indicative of TOH include intermediate signal sequences on T1-weighted image and high signal intensity on T2-weighted images. [43][44][45] TOH edema is regularly pinpointed at the femoral head and may extend to the femoral neck and intertrochanteric region, while being commonly accompanied by joint effusion. [45,46]owever, Malizos et al [43] reported that, while there is there is no connection betwixt the extent of edema and the symptoms' time-length, it appears that TOH with a spared subchondral zone resolves clinically more swiftly.It should be emphasized that patients varied in terms of the amount and extent of edema and subchondral changes, while the time interval between the onset of symptoms and MRI was disparate for each patient included in Malizos study.Contrariwise, a clinical study performed by Ergun et al illustrated that the clinical recovery length was commensurate with the extent of bone marrow edema and the size of subchondral fracture, if that was present. [47]Additionally, Klontzas et al portrayed that the duration of symptoms is statistically associated with the extent of edema, but not with subchondral fracture(s). [48]ifferential diagnosis primarily includes AVN of the hip and less common septic arthritis and malignancy.In septic arthritis an inflammation of the joint and synovium is present.TOH and AVN of the hip are 2 separate clinical entities that exhibit copious distinguishing clinical and radiographic features. [6]AVN MRI findings may reveal a distinct local lesion of the femoral head, subchondral radiolucency (crescent sign), single line sign with edema on T1-weighted image and double line sign with edema on T2-weighted image. [46]ccording to a review by Quaresima et al, while X-rays are broadly the most utilized radiological technique after delivery, MRI has steadily become the gold standard for pregnancy-associated TOH diagnosis through years. [25]Regarding X-ray findings, during the initial 3 to 6 weeks from the onset of symptoms they are usually absent, and when radiographic findings are evident, they include diffuse femoral head osteopenia or periarticular demineralization, yet, the femoral head ordinarily remains intact. [43,46]What more, the lack of subchondral changes is a fundamental indicator of TOH. [49]TOH blood flow and capillary permeability upsurge triggers a rise in radionuclide uptake, thus, a positive bone scan may be detected in all 3 phases and can carry on for weeks after clinical melioration. [43,50,51]Whilst regional migratory osteoporosis is contiguous with TOH in that it is also ordinarily transient; it is characterized by its asymmetric involvement and movement from proximal to distal, advancing unilaterally from the hip region to knee and ankle. [52]aking into account that regional migratory osteoporosis is sporadically connected with BMD alterations, serial bone density calculations may denote the evolution of both bone loss and succeeding recovery of impacted regions. [53]

Prognosis and treatment
Recommended TOH treatment approaches during pregnancy include conservative options such as: non-weight-bearing, wheelchair employment, utilization of crutches for partial weight-bearing, progressive physiotherapy for preventing contractures of the involved hip and mild analgesics like paracetamol and nonsteroidal anti-inflammatory drugs.The objective of these treatments is preclusion of microfractures and pain alleviation, however, the natural course of the disease is not modified. [51]ral and intravenous bisphosphonates along with other antiresorptive agents are not suggested in pregnant and lactating women. [54,55]Bisphosphonates exert influence on fetal skeletal development, causing preterm delivery, fetal growth restriction, neonate transient hypocalcemia and spontaneous abortion.Nonetheless, calcitonin does not cross the placenta and appears to be innocuous during pregnancy, having been shown to diminish symptoms' duration. [54,55]Additionally, the employment of calcitonin during pregnancy might confine TOH duration and recovery time. [56]56] In cases where pregnant TOH patients are not aptly treated, or if TOH does not reverse, subsequent microfractures might bewilder the diagnosis with AVN.The evolving bone injury in conjunction with further bone edema increase might induce necrosis, bone collapse, articular distortion, and proximal femoral fracture. [5]Debatably, TOH might be regarded as an early-stage precursor of AVN. [5,8]Notwithstanding, while TOH generally resolves without sequelae, AVN is customarily an irrevocable and progressive disease, deriving from persistent femoral head blood supply interruption, occasionally provoking permanent joint failure. [8]Total hip arthroplasty or internal fixation is the treatment of choice regarding displaced fractures caused by TOH, whilst internal fixation is opted for non-dislocated fractures and conservative management is proposed for subcapital fractures. [57,58]A review study by Vergara-Ferrer et al [57] examined different therapeutic options (closed reduction internal fixation or open reduction internal fixation with cannulated screws; with or without bone graft utilization and partial or total hip arthroplasty) during third-trimester pregnancy.Eventually, all except for one case healed with no subsequent necrosis, irrespective of the time elapsed since the fracture was discerned. [57]he cohort study by Toussia-Cohen S. et al [32] inquired into the results of LMWH usage for a limited period (3-6 months), inferring that LMWH, as used in the research, is not expected to expose pregnant patients to an increased fracture danger.Nonetheless, if LMWH treatment is projected for an expanded period, advantages and disadvantages should be gingerly assessed before treatment commencement. [32]n general, TOH symptoms typically resolve within the first 2 months postnatal.In the majority of cases, MRI findings return to normal over a 3 to 6 month period after delivery. [57,58]owever, there have been documented cases resolving only after 6 years from diagnosis, [58] while recurrence in subsequent pregnancies has not been described. [26]o paper has highlighted TOH impact during pregnancy regarding the mode of delivery, although an elective Caesarean section has been widely featured to protect women from birth-related injuries. [59]In the vast majority of pregnancy-associated TOH cases, the potential occurrence of severe hip pain and joint functional limitation has rendered this condition a non-obstetric indication for elective Caesarean section. [59]ccording to the literature review conducted by Quaresima et al, more than 70% of Caesarean delivery has been executed with regards to the consequential hip functional limitation. [25]It is remarkable that Caesarean section rates at this level are well above the World Health Organization recommended ones. [60]In the most recent cohort study carried out by Toussia-Cohen et al, where clinicians with augmented experience with TOH patients were included, only 5 women (31.2%) delivered by elective Caesarean section due to TOH, while all women were given the option of vaginal delivery. [32]

Conclusion
TOH in pregnancy and lactation is preponderantly a self-limiting disorder, usually resolving 6 to 8 months postpartum.Etiology and pathophysiological mechanisms have not been consummately determined.In general, the disease is chiefly unilateral, presumably triggered by impaired venous return with bone marrow edema.
Opportune diagnosis is pivotal for optimal patient management, avoiding potentially debilitating effects resulting from other diseases of similar presentation, such as AVN of the femoral head.MRI is irrefutably the most apposite imaging examination and clinicians should demonstrate a low threshold for ordering an MRI scan when dealing with pregnant women with persistent hip pain.
Treatment is ordinarily conservative, including analgesics and protected weight-bearing for prevention of pathological fractures, commonly up to a few weeks postpartum.Bisphosphonates are not recommended during pregnancy but calcitonin might curtail recovery time duration.In cases of femoral neck fractures, surgical treatment can be a vital option, whilst conservative management is customarily proposed in terms of subcapital fractures.
Further research is requisite since there are no globally established strategies regarding consummate follow-up, therapy and clinical management of pregnancies complicated by TOH.

Table 1
Galanis et al. • Medicine (2023) 102:41Medicine Main reviewed resources.bonemineral density (BMD) occurs during pregnancy.During postpartum, BMD reduces further and is related to the length of breastfeeding period.Reversal of pregnancy-induced changes in body composition is also associated to breastfeeding status, as the decrease in fat mass postpartum is postponed in women who continue to breastfeed.Pregnancy and lactation invoke novel regulatory systems in women to meet the challenges for increased delivery of minerals.In the long term, most studies delineate that parity and lactation pose no adverse risk of low bone mass or fractures, and in fact a number of studies have suggested that parity and lactation confer a protective effect.Lastly, these adaptations during pregnancy and lactation have important impact on preexisting disorders of bone and mineral metabolism.
A systematic bone loss takes place during PPA, and after resumption of menstruation BMD recovers despite continued lactation.Nonetheless, the time of bony recovery back to postpregnancy levels appears to be modulated marginally by lactation habits.
The overall severity of complaints is not associated to previous peripartum pelvic pain or type of deliveries or to commonly used tests.Further study on the role of clinical examination, includ-ing passive flexion and internal rotation of the hip joints, was propounded Hip diseases resulting in significant clinical impairment appear infrequent during pregnancy and early postpartum.Transient osteoporosis of the hip (TOH) was the most frequently encountered pregnancy-related hip disease.Contrariwise, osteonecrosis was rare.Stress fractures of the femoral head seem an important cause of pregnancy-related hip disease.Diagnosis of pregnancy-related covert fractures of the femoral head is cardinal because it might reveal an underlying bone disease.(Continued)www.md-journal.com